1. Field of the Invention
The invention is related to the field of communications and, in particular, to providing alerting to subscribers of long duration sessions in communication networks.
2. Statement of the Problem
One type of communication network gaining popularity is an IP Multimedia Subsystem (IMS) network. As set forth in the 3rd Generation Partnership Project (3GPP), IMS provides a common core network having access-agnostic network architecture for converged networks. Service providers are accepting this architecture in next generation network evolution. The IMS architecture is initially defined by the 3GPP to provide multimedia services to mobile subscribers over an Internet Protocol (IP) network. IP networks have become the most cost savings bearer network to transmit video, voice, and data. IMS uses the advantage of IP networks to provide multimedia services for IMS subscribers on an IMS platform. The signaling used within IMS networks is Session Initiation Protocol (SIP). IMS defines the standard SIP interface between application servers, the IMS core network (CSCF), the IMS subscriber, the IMS database (HSS), and IMS billing elements. These standards can reduce the network integration costs and let the subscriber enjoy more stable services.
IMS sessions may be established for a variety of reasons, such as voice calls, IP TV, IP movies, online gaming, etc. Unlike traditional telephony calls, IMS sessions such as these may have long durations, such as days, weeks, or months. A long duration IMS session may be intentional by the subscriber, such as if he/she is playing an online game for an extended period of time. The long duration IMS session may also be unintentional where the subscriber forgets to log off of the session. In either case, long duration IMS sessions can be costly to the user if they are billed on a time basis.
One problem with present IMS networks is that subscribers are only notified of long duration sessions in a billing invoice (e.g., a monthly billing invoice) that itemizes the IMS sessions during a billing period. Unfortunately, the subscriber may receive a billing invoice having very high and unexpected costs due to one or more long duration IMS sessions.